A wireless type electric power supply system has been proposed which charges a battery equipped in a vehicle when a vehicle is parked in a parking space by supplying electric power from a power feeding coil unit installed on a parking space, where a vehicle can be parked, to a power receiving coil unit provided on the vehicle side via a magnetic field.
In this wireless type electric power supply system, in order to detect that any foreign metals which may be affected by a magnetic field are mixed between the power feeding coil unit and the power receiving coil unit, the development of a power feeding coil unit equipped with a sensor has been under review.
However, since the power feeding coil unit is installed on the road surface of the parking space, there is a problem that an external stress is easily to be applied to built-in portions when a vehicle runs on the power feeding coil unit, and thus, studies for improving the load bearing performance of the power feeding coil unit are becoming active.